deQuervain’s tendinitis is a condition brought on by irritation or swelling
of the tendons found along the thumb side of the wrist (Figure 1). The irritation
causes the compartment (lining) around the tendon to swell, changing the shape
of the compartment; this makes it difficult for the tendons to move as they
should. The swelling can cause pain and tenderness along the thumb side of the
wrist, usually noticed when forming a fist, grasping or gripping things, or
turning the wrist.

What causes it?

The cause of deQuervain’s tendinitis is an irritation of the tendons at the
base of the thumb. For example, awkward hand positions required by a new mother
in caring for an infant is a common cause of this condition.

Signs and symptoms.

Pain over the thumb side of the wrist is the main symptom. The pain may appear
either gradually or suddenly. It is felt in the wrist and can travel up the
forearm. The pain is usually worse with use of the hand and thumb, especially
when forcefully grasping things or twisting the wrist. Swelling over the thumb
side of the wrist is noticed and may be accompanied by a fluid-filled cyst in
this region. There may be an occasional “catching” or “snapping” when moving
the thumb. Because of the pain and swelling, it may be difficult to move the
thumb and wrist, such as in pinching. Irritation of the nerve lying on top of
the tendon sheath may cause numbness on the back of the thumb and index finger.

Diagnosis.

A Finkelstein test is generally performed. In this test, the patient makes
a fist with the fingers over the thumb. The wrist is then bent in the direction
of the little finger (Figure 2). This test can be quite painful for the person
with deQuervain’s tendinitis. Tenderness directly over the tendons on the thumb-side
of the wrist is the most common finding, however.

Treatment.

The goal is to relieve the pain caused by the irritation and swelling. In some
cases, your doctor may recommend resting the thumb and wrist by wearing a splint.
Anti-inflammatory medication taken by mouth or injected into that tendon compartment
may help reduce the swelling and relieve the pain. In some cases, simply not
doing the activities that cause pain and swelling may allow the symptoms to
go away on their own. When symptoms are severe or do not improve, surgery may
be recommended. The surgery opens the compartment (covering) to make more room
for the irritated tendons (Figure 3). Normal use of the hand can usually be
resumed once comfort and strength have returned. Your hand surgeon can advise
you on the best treatment for your situation.

Figure 1Swelling about the tendons to the base of the thumb results in painful
motion.